Analysis of organic electrode reactions by a thin layer electrochemical Raman method

在本项目中，我们首先通过发展薄层电化学共振拉曼方法分析了金属离子存在下的氯丙腈的还原过程。因此，在均相溶液中的反应和在电极表面上的反应的差异变得明显。此外，我们还研究了碱土金属离子存在下四氰基喹二甲烷(TCNQ)的电化学还原过程。在乙腈中，在Ba2+和Mg2+存在下，TCNQ还原过程的循环伏安曲线表明，生成自由基阴离子的还原过程对金属离子的存在没有影响，而形成二负离子的还原过程对金属离子的影响较大。在氧化扫描中观察到两个氧化峰，这两个峰归因于吸附沉积物的脱附。EQCM测试表明，电极表面生长的是一个金属离子和两个自由基阴离子组成的单元。并提出了自由基阴离子二聚体生成含金属离子的结构生长模型，其中形成TCNQ阴离子是关键步骤。因此，为了确定结构生长的关键步骤--双阴离子的形成，我们用共振拉曼光谱对沉积进行了分析。在514.5 nm激光激发下，共振拉曼光谱观察到了TCNQ二阴离子的氧化态，从而证实了所提出的模型。在785 nm激光激发下，观察到主要产物为TCNQ自由基阴离子。

In this project, at first, we analyzed the reduction processes of chioranil in the presence of metal cations by developing a thin layer electrochemical resonance Raman method. Consequently, the differences in the reactions between in the homogeneous solutions and on the electrode surface have become clear. Also, the difference depending on the sort of metal cations has analyzed.In addition, we studied the electrochemical reduction process of tetracyanoquinodimethane (TCNQ) with the presence of the alkaline earth metal ion. Cyclic voltammogram of TCNQ reduction process with the presence of barium ion and magnesium ion in acetonitrile showed that the reduction process forming radical anion has no effect of the presence the metal ion, but the reduction process forming dianion has large effect of the metal ion. And in the oxidation scan, two oxidation peaks were observed which were attributed to desorption of adsorption deposits. From the EQCM measurement, it was appeared that the unit one metal ion with two radical anions grows on the electrode surface. And we could submit the structural growth model where radical anion dimer produced containing metal ion with the key step that forming TCNQ dianion. Therefore, to confirm the formation of dianion which is key step of the structural growth, we analyzed the deposit with using resonance Raman measurement. In the excitation using 514.5 nm laser, oxidant of TCNQ dianion was observed from the resonance Raman spectra, so the submitted model was confirmed. And also, in the excitation of 785 nm laser, TCNQ radical anion which was major product was observed.